I got a 99 chevy suburban 6.5td and when im on the highway only at 60+mph when you let off the pedal at 60+ the rpms will drop down to 1500 instantle and then when you ease on it aain very little the rpms will go right up to 2400 if im going 65. so there is no inbetween just right up to 2400. could it be the pedal.

this sounds somewhat normal to me....the PCM sees you wanting to slow down when you release throttle...so the RPM drops and the trans free wheels....and when you touch the pedal again, the pcm goes straight to speed maintenance and revs the engine up to give you available boost.

The engine doesn't have a load on it, until 2400 rpm, so it'll fly up in rpms pretty fast.

It's the same idea as being in park, you can rev much faster in park.

You're just being paranoid :p:

Sounds normal to me.

by the way...the "symptom" you described...isn't known as sputtering...sputtering is like when an engine runs out of gas or has a hard time starting

by the way...the "symptom" you described...isn't known as sputtering...sputtering is like when an engine runs out of gas or has a hard time starting

Tsk tsk... FUEL :p:

well diesels don't sputter, they cough :p:...gassers sputter....so GAS:P:

well diesels don't sputter, they cough

Cause they smoke. :D

tsk tsk....they have muffler cancer :p:...i love cold starts in the morning, cause my neighbours are pricks and i always leave this black stain on there little ****ing tree they put at the end of my driveway that prevents me getting in in one shot